In recent years, a printer using an ink-jet recording system such as an ink-jet printer and an ink-jet plotter has been widely used for industrial use, for example, manufacturing a color filter for forming an electronic circuit or for a liquid crystal display, and manufacturing an organic EL display as well as a printer for consumers.
A liquid ejection head for ejecting a liquid is installed on such a printer of an ink-jet system as a print head. Such a print head including a heater in an ink channel filled with an ink as pressurizing means, and a thermal head system in which an ink is heated and boiled by a heater and the ink is pressurized by bubbles generated in the ink channel and ejected as liquid droplets through an ink ejection hole, and a piezoelectric system in which a wall of a part of the ink channel filled with an ink is bent and displaced by a displacement element, the ink in the ink channel is mechanically pressurized and ejected as liquid droplets through an ink ejection hole is generally known.
In addition, in regard to such a liquid ejection head, there is a serial system in which recording is performed while moving a liquid ejection head in a direction (main scanning direction) orthogonal to a transporting direction (sub scanning direction) of a recording medium, and a line system in which recording is performed on a recording medium which is transported in a sub scanning direction in a state in which the liquid ejection head longer than the recording medium in a main scanning direction is fixed. The line system has an advantage in that high speed recording is possible because it is not necessary to move the liquid ejection head as in the case of the serial system.
Even in a case of the liquid ejection head of the serial system or the line system, in order to print the liquid droplets with high density, it is necessary to increase the density of ejection holes ejecting liquid droplets, which are formed in the liquid ejection head.
Accordingly, a liquid ejection head which is configured by laminating a channel member including a manifold and ejection holes connected to each other through a plurality of pressurizing chambers from the manifold and a piezoelectric actuator substrate provided so as to cover the plurality of pressurizing chambers and including a plurality of displacement elements having a piezoelectric ceramic layer interposed between a plurality of individual electrodes and a common electrode facing the plurality of individual electrodes is known (for example, see PTL 1). In this liquid ejection head, the pressurizing chambers respectively connected to the plurality of ejection holes are arranged in a form of a matrix, and an ink is ejected from the ejection holes and printing in a main scanning direction with a resolution of 600 dpi is possible by displacing displacement elements of an actuator unit provided so as to cover the pressurizing chambers by deforming a piezoelectric body.